The invention relates to operating child safety barriers, such as those placed across the top of a staircase to prevent infants or children from wandering onto a stairway.
Child safety barriers (gates) are found across entrances at the tops of stairways in the homes of many people with infants or small children. Safety codes can require that such gates be securely fastened to structural elements on either side of the entrance on top of a stairway, rather than be held in place by pressure and friction. It is desirable that such gates be easily operated by adults, but not by small children.
The invention features a child safety gate having a latching assembly that can be engaged with a corresponding receptacle assembly, and then released by moving a single knob in two consecutivesenses, such as in a linear sense and then a rotational sense. The word xe2x80x9csensexe2x80x9d is used herein to indicate a direction of motion.
In one broad aspect a child safety barrier, is disclosed that includes a receptacle assembly rigidly mountable to a structural element on one side of a passageway, a gate with a latch housing, the gate being mountable to a structural element on an opposite side of the passageway and positionable to span across the passageway, a retractable plunger assembly disposed at least partially within the latch housing and extendable from the latch housing to engage the receptacle assembly and retain the gate in a closed position and a knob exposed at a surface of the latch housing for manipulation by an operator, the knob being movable in a first sense to a first position and movable from the first position in a second sense to cause the plunger assembly to retract from the receptacle assembly to release the gate for opening. The retractable plunger assembly can include an upper plunger extendable from an upper portion of the latch housing to engage the receptacle assembly and a lower plunger extendable from a lower portion of the latch housing to engage the receptacle assembly at a point vertically spaced from the upper plunger. Both the upper and lower plungers may become operatively coupled to the knob as the knob is moved in the first sense and both the upper and lower plungers may retract as the knob is moved from the first position in the second sense. The child safety barrier may also include a plunger spring positioned between the upper and lower plungers to bias the upper and lower plungers toward a position fully extended from the latch housing. The child safety barrier may also include an adapter securely attached to the knob and a rotatable member coupled to the plunger assembly. The rotatable member may have a recess for receiving the adapter when the knob is moved in the first sense, thereby coupling the knob to the plunger assembly. The rotatable member may have a cam that rotates as the knob is moved from the first position in the second sense. The child safety barrier may also include levers pivotally mounted to pivot points, each lever having a first end in contact with the cam and a second end coupled to one of either the upper or lower plungers. Each plunger may have a slot for receiving the second end of the associated lever, and motion of each lever causes motion of the associated plunger. The contour of the cam may be such that the rotatable member is rotatable up to a particular angle, such as less than approximately 90xc2x0, or between approximately 20xc2x0 and 70xc2x0, or about approximately 45xc2x0 without causing any lever motion. The child safety barrier can also include a knob-spring coupled to the knob and positioned to bias the knob toward a position such that the adapter is disengaged from the recess of the rotatable member. The child safety barrier may also have a lip inside the latch housing positioned to contact the adapter when the knob is moved from the first position, in the second sense, and prevent the adapter from disengaging from recess of the rotatable member. The child safety barrier may also have a cam-spring with a first end attached to the latch housing and a second end attached to the rotatable member, the cam-spring being positioned to bias the rotatable member toward a position such that each plunger is allowed to fully extend through the latch housing. The knob may be movable in the first sense in an axial direction to the first position at least partially recessed within the latch housing. The knob may be movable from the first position in the second sense, a rotational direction. The gate may be a substantially rigid structure. The child safety barrier can also include a second, independently operable knob exposed at a side of the gate opposite the first knob. A gate swing limiter may be A; securable to the receptacle assembly to prevent swinging the gate in a particular direction, such as toward a staircase. The child safety barrier may also have a knob spring positioned to bias the knob to a position extending through an opening in the latch housing. The child safety barrier may include a coupling device rigidly secured to the knob and a rotatable plunger actuating assembly coupled to the retractable plunger assembly, wherein the coupling device engages the plunger actuating assembly when the knob is pushed in to a depressed position and the knob spring is compressed. A lip may be positioned to prevent the coupling device from disengaging from the plunger actuating assembly when the knob is turned from the depressed position. The plunger actuating assembly may include a rotatable cam having an irregular surface and a pivotal lever having a first end in contact with the cam surface and a second end coupled to a slot in the plunger assembly wherein rotation of the cam causes the lever to pivot and the plunger to move.
In another broad aspect, a method of operating a child safety barrier at a passageway is disclosed comprising rigidly mounting a receptacle assembly to a structural element on one side of a passageway, mounting a barrier comprising a latching mechanism to a structural element at a first side of the passageway and positioning the barrier to span across the passageway so the latching mechanism engages with the receptacle assembly to maintain the barrier in a closed position, pushing a knob that is coupled to the latching mechanism thereby moving the knob to a partially recessed position and turning the knob from the partially recessed position to disengage the latching mechanism from the receptacle assembly. Moving the knob to a partially recessed position may require applying between approximately three and seven pounds of force or approximately five pounds of force. Turning the knob may require applying between approximately three to seven inch-pounds of torque or approximately five inch-pounds of torque. The knob may need to be turned at least approximately 45xc2x0 before the latching mechanism disengages from the receptacle assembly. The method may also include swinging the barrier to an open position by pivoting the barrier about a pivot point. The method may also include swinging the barrier to a closed position and listening for an audible click to confirm that the latching mechanism engages with the receptacle assembly. The method may include attaching a swing direction limiter to the receptacle assembly to prevent the gate from swinging open in one of the possible directions.
In yet another broad aspect, a child safety barrier includes a receptacle assembly rigidly mountable to a structural element on one side of a passageway, a gate comprising a latch housing, the gate being mountable to a structural element on an opposite side of the passageway and positionable to span across the passageway, a retractable plunger assembly disposed at least partially within the latch housing and extendable from the latch housing to engage the receptacle assembly and retain the gate in a closed position, a knob extending through an opening in the latch housing for manipulation by an operator a knob spring positioned to bias the knob to a position extending through an opening in the latch housing, a coupling device rigidly secured to the knob and a rotatable plunger actuating assembly coupled to the retractable plunger assembly. The coupling device engages the plunger actuating assembly when the knob is pushed in to a depressed position and the plunger actuating assembly rotates to retract the plunger assembly when the knob is turned from the depressed position to release the gate from the receptacle assembly for opening. A lip can be positioned inside the latch housing to prevent the coupling device from disengaging from the plunger actuating assembly when the knob is turned from the depressed position. The plunger actuating assembly can include a rotatable cam having an irregular surface and a pivotal lever having a first end in contact with the cam surface and a second end coupled to a slot in the plunger assembly. Rotation of the cam may cause the lever to fly, pivot and the plunger to move.
Implementation of the techniques and apparatus described herein may provide one or more of the following advantages. An intuitive, one hand operation latching mechanism is provided. A particular implementation includes a knob that is pushed then turned to release the latching mechanism from a mating receptacle assembly. Such an implementation may be particularly desirable because an adult carrying a child, for example, could easily open the gate with one hand, step through the passageway and re-close the gate. Since the knob has tight tolerances between parts, pinch-free operation is also provided.
Gates can typically be opened in either direction and swung to a closed and latched position. When the gate is swung to a closed and latched position, an audible click can be heard when the latching assembly engages with a mating receptacle assembly. This click provides a user with a straightforward indication that the gate properly latched when closed.
Optionally, the gate can be configured to swing open in only one direction, for example, away from a staircase. Additionally, the width of the gate is typically adjustable to fit across different sized passageways.